code: def test_get_tables(self, handler):
      tables = self.get_table_names(handler)
      assert (
          "rentals" in tables
      ), f"expected to have 'rentals' table in the db but got: {tables}"
  
file_path: mindsdb/tests/handler_tests/test_postgres_handler.py
imports: import time
  import pytest
  import docker
  from mindsdb.integrations.handlers.postgres_handler.postgres_handler import PostgresHandler
  from mindsdb.api.executor.data_types.response_type import RESPONSE_TYPE
label_desc: Use image node_id 4 for calling the TestPostgresHandler obj's underlying member method code with example usage: obj.test_get_tables(handler) without return types